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You searched for: subject:"boundary conditions"
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[texts]2. Maths IJAMSS On The Convergence Of Eigenvalues And Tawik Masrour Morocco
In this paper we are interested in the problem of convergence of the eigenvalues and eigenfunctions of the Laplacian with Went zell-Robin boundary condition to the eigenvalues and eigenfunctions of the Laplacien with Dirichlet boundary condition when the Robin parameter tends to infinity. We show in particular that the convergence of eigenfunctions is better than the usual internal convergence in and boundary convergence in 
Keywords: Laplacien; Went Zell-Robin Boundary Conditions
[texts]NASA Patent Abstracts Bibliography: A Continuing Bibliography - NON
This report lists NASA patent abstracts recently announced in the NASA STI Database.
Keywords: CLOCKS; BOUNDARY CONDITIONS; ACCURACY; FINITE ELEMENT METHOD; SYSTEMATIC ERRORS
Downloads: 125
[texts]A SUGGESTION CONCERNING THE BOUNDARY CONDITIONS OF B STARS - Huang, S.-S.
Expected boundary conditions of b-stars
Keywords: B STARS; BOUNDARY CONDITIONS; MAGNETIC PROPERTIES; B STAR; BOUNDARY
Downloads: 50
[texts]Propellant Densification for Shuttle: The SSME Perspective - Greene, William D.
The subject of cryogenic propellant densification as a potential upgrade to the Space Shuttle is a subject that has been raised on several occasions over the last decade. Due to advancements in densification technology made as a part of and in parallel to the X-33 project, the subject was raised and studied once again in May 2001. Across the Space Shuttle program people from many disciplines converged to discuss issues and perform trade studies to determine whether densified propellants was wort...
Keywords: AIRFOILS; GUSTS; AEROACOUSTICS; BOUNDARY CONDITIONS; DYNAMIC RESPONSE; COMPUTATIONAL GRIDS; DECOMPOSITION
Downloads: 130
[texts]Computational technique for compressible vortex flows using the integral equation solution - Kandil, Osama A
The steady full-potential equation is written in the form of Poisson's equation, and the solution for the velocity field is expressed in terms of an integral equation. The integral solution consists of two surface integrals and one volume integral. The solution is obtained through successive iteration cycles. Each cycle of iteration consists of two sub-cycles, an inner cycle for wake relaxation and an out cycle for the strength of the source distribution integrals representing the flow compressi...
Keywords: BOUNDARY VALUE PROBLEMS; DECOMPOSITION; DOMAINS; INTERFACES; BOUNDARY CONDITIONS; NUMERICAL ANALYSIS; PARALLEL PROCESSING (COMPUTERS); SPECTRAL METHODS
Downloads: 57
[texts]Results of Mechanical Testing for Pyroceram(tm) Glass-Ceramic - Choi, Sung R.
Mechanical testing for Pyroceram (trademark) 9606 glass-ceramic fabricated by Corning was conducted to determine mechanical properties of the material including slow crack growth.Valid testing was not achieved in tension, compression, and shear testing due to inappropriate test specimen configurations provided and primarily due to the existence of fortified layer( in tension).
Keywords: BOUNDARY CONDITIONS; DIRECT NUMERICAL SIMULATION; GALERKIN METHOD; DECOMPOSITION; PERFECTLY MATCHED LAYERS; REFLECTANCE; DIFFERENTIAL EQUATIONS
Downloads: 95
[texts]USE OF LASER SOUNDING TO DETERMINE CERTAIN ATMOSPHERIC CHARACTERISTICS - ZAKHAROV, V. M.
EXPERIMENTAL RESULTS OF ATMOSPHERIC SOUNDING BY LASER LOCATOR AT WAVELENGTHS OF 694.3 AND 1,060 NM ARE PRESENTED. TOTAL REVERSE DISPERSION PROFILES WERE OBTAINED; THE SOUNDING DATA AT NACREOUS CLOUD ALTITUDE COMPARES FAVORABLY WITH OTHER LIDAR MEASUREMENTS. DATA WAS PROCESSED FROM DUAL-FREQUENCY SOUNDING FOR SIGNAL DISTRIBUTION, DETERMINED BY REVERSE MOLECULAR AND AEROSOL DISPERSION. ATMOSPHERIC DENSITY IS COMPUTED BY REVERSE MOLECULAR DISPERSION.
Keywords: BOUNDARY CONDITIONS; ENVIRONMENTS; HEAT TRANSFER COEFFICIENTS; THERMAL ENERGY; TURBINE BLADES; SURFACE PROPERTIES; TEMPERATURE EFFECTS; THERMODYNAMIC PROPERTIES
Downloads: 61
[texts]Scientific Toy - NON
Tensegritoy, inspired by the tensegrity concepts of R. Buckminster Fuller, is an erector set like toy designed to give students an understanding of structural stability. It is used by children, architects, engineers, and teachers. The manufacturer, Tensegrity Systems Corporation, also offers a collapsible point of purchase display which incorporates technology developed for space station trusses described in ''NASA Tech Briefs.'' The tech brief described deployable trusses that can be collapsed ...
Keywords: COMPUTATIONAL FLUID DYNAMICS; BOUNDARY CONDITIONS; SUPERSONIC INLETS; SUPERSONIC FLOW; UNSTEADY FLOW; SUBSONIC FLOW; COMPUTATIONAL GRIDS
Downloads: 123
[texts]Evaluation of Various Types of Wall Boundary Conditions for the Boltzmann Equation
This paper presents the evaluation of several solid wall boundary conditions when used in the numerical solution of the Boltzmann equation using the finite-difference/finitevolume methods. Five solid wall boundary conditions are considered: (a) adsorption, (b) specular reflection, (c) diffuse reflection, (d) Maxwellian reflection, and (e) adsorptive Maxwellian reflection. The boundary conditions are applied on a two-dimensional discretized velocity space mesh.Methods for applying the same bounda...
Keywords: Boltzmann Equation; Non-equilibrium Hypersonic Flows; Wall Boundary Conditions for Boltzmann Equation
Downloads: 6
[texts]Dynamic Stall Measurements and Computations for a VR-12 Airfoil with a Variable Droop Leading Edge - Martin, P. B.
High density-altitude operations of helicopters with advanced performance and maneuver capabilities have lead to fundamental research on active high-lift system concepts for rotor blades. The requirement for this type of system was to improve the sectional lift-to-drag ratio by alleviating dynamic stall on the retreating blade while simultaneously reducing the transonic drag rise of the advancing blade...
Keywords: REUSABLE LAUNCH VEHICLES; TRAJECTORY PLANNING; BOUNDARY CONDITIONS; ALGORITHMS; FLIGHT PLANS; SIMULATION
Downloads: 74
[texts]Suspension system for gimbal supported scanning payloads - NON
Gimballed scanning devices or instruments are the subject of this invention. Scanning is an important aspect of space science. To achieve a scan pattern some means must be provided which impart to the payload an oscillatory motion. Various forms of machines have been employed for controllably conferring on scanning instruments predetermined scan patterns. They include control moment gyroscopes, reaction wheels, torque motors, reaction control systems, and the like...
Keywords: CAVITATION FLOW; COMPUTATIONAL FLUID DYNAMICS; IMPELLERS; TURBINE PUMPS; BOUNDARY CONDITIONS; EQUATIONS OF STATE; PRESSURE DISTRIBUTION
Downloads: 82
[texts]Testing Facility Uncertainty Analyses for RBCC Systems Testing - Hudson, Susan T.
The Rocket Based Combined Cycle (RBCC) engine is expected to evolve based upon past combined-cycle propulsion test experience/data and new extensive test data. Currently, it is envisioned that a portion of the component and system testing will be pursued at NASA Stennis Space Center (SSC). To realize the greatest benefit of the test data, uncertainty analyses are being performed on the relevant RBCC components and systems to be tested at NASA SSC to ascertain the needed measurement requirements...
Keywords: HEAT SHIELDING; BOUNDARY CONDITIONS; ABLATIVE MATERIALS; CARBONACEOUS MATERIALS; SURFACE PROPERTIES; SURFACE VEHICLES; REACTION KINETICS; REENTRY EFFECTS
Downloads: 42
[texts]Testing of Gyroless Estimation Algorithms for the Fuse Spacecraft - Harman, R.
This paper documents the testing and development of magnetometer-based gyroless attitude and rate estimation algorithms for the Far Ultraviolet Spectroscopic Explorer (FUSE). The results of two approaches are presented, one relies on a kinematic model for propagation, a method used in aircraft tracking, and the other is a pseudolinear Kalman filter that utilizes Euler's equations in the propagation of the estimated rate...
Keywords: LEADING EDGES; STAGNATION FLOW; MULTIGRID METHODS; INVISCID FLOW; FLOW EQUATIONS; BOUNDARY CONDITIONS; ITERATION
Downloads: 83
[texts]Wind-Tunnel Investigations of Diving Brakes - Fucha, D
Unduly high diving speeds can be effectively controlled by diving brakes but their employment involves at the same time a number of disagreeable features: namely, rotation of zero lift direction, variation of diviving moment, and, the creation of a potent dead air region.
Keywords: SPACE-TIME CE/SE METHOD; BOUNDARY CONDITIONS; FLOW EQUATIONS; ADVECTION; SHOCK TUBES
Downloads: 51
[texts]Full-Span Tilt-Rotor Aeroacoustic Model - McClure, Megan S.
Tilt rotors are a new breed of subsonic aircraft developed for both military and civil aviation. The current production of the military V-22 Osprey and the launch decision of the BA-609 civil tilt rotor will certainly enhance the U.S. military and economic competitive status in the international aviation arena. In addition, civil tilt rotors have the potential to increase air transportation throughput in congested airports by off-loading busy runways...
Keywords: BOUNDARY CONDITIONS; CRYOGENIC COOLING; HEAT TRANSFER; STROUHAL NUMBER; STEADY FLOW; ENTHALPY; PREDICTIONS; KINETIC ENERGY
Downloads: 69
[texts]Control of Torsional Vibrations by Pendulum Masses - Stieglitz, Alber
Various versions of pendulum masses have been developed abroad within the past few years by means of which resonant vibrations of rotating shafts can be eliminated at a given tuning. They are already successfully employed on radial engines in the form of pendulous counterweights. Compared with the commonly known torsional vibration dampers, the pendulum masses have the advantage of being structurally very simple, requiring no internal damping and being capable of completely eliminating certain v...
Keywords: THIN WALLED SHELLS; STRESS FUNCTIONS; DIFFERENTIAL EQUATIONS; MODULUS OF ELASTICITY; BOUNDARY CONDITIONS
Downloads: 105
[texts]A Simple Theory of Capillary-Gravity Wave Turbulence - Glazman, Roman E
Employing a recently proposed 'multi-wave interaction' theory, inertial spectra of capillary gravity waves are derived. This case is characterized by a rather high degree of nonlinearity and a complicated dispersion law. The absence of scale invariance makes this and some other problems of wave turbulence (e.g., nonlinear inertia gravity waves) intractable by small-perturbation techniques, even in the weak-turbulence limit...
Keywords: CORONAL HOLES; MAGNETOHYDRODYNAMIC FLOW; SOLAR CORONA; BOUNDARY CONDITIONS; MATHEMATICAL MODELS; SIMULATION
Downloads: 58
[texts]A Liquefier for Mars Surface Propellant Production - Salerno, Lou J.
NASA's planned Mars exploration missions will require that cryogenic propellants be manufactured on the surface. The present scenario calls for oxygen and methane gases to he produced using the carbon dioxide atmosphere plus seed hydrogen brought from Earth. Gases will require liquefaction for both storage on the Martian surface and for use in the ascent vehicle. The planned liquefaction rates range from 12.6 g/hr of oxygen for the 2003 robotic mission to 2500 g/hr for the later human missions...
Keywords: RAMAN SPECTROSCOPY; COMBUSTION CHAMBERS; COMPUTATIONAL FLUID DYNAMICS; SUPERSONIC COMBUSTION; TEMPERATURE MEASUREMENT; INJECTORS; EXPERIMENT DESIGN; BOUNDARY CONDITIONS
Downloads: 87
[texts]Mission safety evaluation report for STS-48, postflight edition - Clatterbuck, Guy E.
Space Shuttle Discovery was launched into a 57 deg inclination orbit from the Kennedy Space Center (KSC) Launch Complex 39A at 7:11 p.m. EDT on 12 Sep. 1991. STS-48 was the second mission since return-to-flight to have KSC as the planned end-of-mission landing site, and the first mission to have a planned night landing at KSC. However, due to weather conditions at KSC, Discovery flew one extra orbit and landed at Edwards AFB, Calif...
Keywords: BOUNDARY CONDITIONS; ELECTROMAGNETIC SCATTERING; BROADBAND; CONDUCTORS; DOMAINS; ELECTRICAL IMPEDANCE; FINITE DIFFERENCE THEORY; SURFACE PROPERTIES; TIME; DIELECTRICS
Downloads: 73
[texts]Surficial Geology of the Spirit Rover Traverse in Gusev Crater: Dry and Desiccating Since the Hesperian - Golombek, M. P
The Spirit rover landed successfully in a low albedo portion of Gusev crater at 14.5692 deg S, 175.4729 deg E on January 3, 2004 and has traversed about 3.5 km over 180 sols through cratered plains to Bonneville crater and the Columbia Hills. Gusev, a 160 km diameter Noachian crater that lies at the terminus of the 900 km long Ma'adim Vallis, was selected as a landing site to search for evidence of previous liquid water flow and/or ponding...
Keywords: AEROACOUSTICS; CONFERENCES; NUMERICAL ANALYSIS; SOUND WAVES; BOUNDARY CONDITIONS; AIRCRAFT NOISE; SHEAR FLOW; FLOW VELOCITY; GUSTS; TURBOMACHINERY
Downloads: 75
[texts]Aerodynamics for Revolutionary Air Vehicles - Sellers, William L., III
Aeronautics research has seriously declined partly because of the perception that it is a mature science and only incremental improvements are possible. Recent aeronautics roadmapping activities at NASA Langley paint a different picture of the future. Breakthroughs are still felt to be possible if we expand the current design space of today's vehicles and optimize the airspace and vehicles as a system...
Keywords: PRESSURE MEASUREMENT; SUBSONIC WIND TUNNELS; BOUNDARY CONDITIONS; COMPUTATIONAL FLUID DYNAMICS; PRESSURE SENSORS
Downloads: 181
[texts]Investigation of Low Power Operation in a Loop Heat Pipe - Ku, Jentung
This paper presents test results of an experimental study of low power operation in a loop heat pipe. The main objective was to demonstrate how changes in the vapor void fraction inside the evaporator core would affect the loop behavior, The fluid inventory and the relative tilt between the evaporator and the compensation chamber were varied so as to create different vapor void fractions in the evaporator core...
Keywords: ALGORITHMS; NAVIER-STOKES EQUATION; UNSTRUCTURED GRIDS (MATHEMATICS); UPWIND SCHEMES (MATHEMATICS); BOUNDARY CONDITIONS; MACH NUMBER; EIGENVALUES
Downloads: 88
[texts]Operationally Efficient Propulsion System Study (OEPSS): OEPSS Video Script - Wong, George S.
The OEPSS video film, along with the OEPSS Databooks, provides a data base of current launch experience that will be useful for design of future expendable and reusable launch systems. The focus is on the launch processing of propulsion systems. A brief 15-minute overview of the OEPSS study results is found at the beginning of the film. The remainder of the film discusses in more detail: current ground operations at the Kennedy Space Center; typical operations issues and problems; critical opera...
Keywords: BOUNDARY CONDITIONS; AEROACOUSTICS; COMPUTATION; SIMULATION; ENCOUNTERS; DISSIPATION; ALGORITHMS; FINITE ELEMENT METHOD
Downloads: 64
[texts]Space Electrochemical Research and Technology - NON
Individual papers presented at the conference address the following topics: development of a micro-fiber nickel electrode for nickel-hydrogen cell, high performance nickel electrodes for space power application, bending properties of nickel electrodes for nickel-hydrogen batteries, effect of KOH concentration and anions on the performance of a Ni-H2 battery positive plate, advanced dependent pressure vessel nickel hydrogen spacecraft cell and battery design, electrolyte management considerations...
Keywords: POTENTIAL FLOW; HELIOSPHERE; SOLAR WIND; SHOCK WAVES; MAGNETIC FLUX; BOUNDARY CONDITIONS; MATHEMATICAL MODELS; SOLAR WIND VELOCITY
Downloads: 126
[texts]Saturn, 1959 - NON
In October 1958, the National Aeronautics and Space Agency (NASA) was asked to absorb the Army Ballistic Missile Agency (ABMA) space group, but an agreement was reached two months later for the group to remain with the Army while being responsive to NASA. This decision was to be reconsidered and reversed within a year. The competition in large launch vehicles between NASA, ARPA (Advanced Research Projects Agency), Air Force, and Army begun in 1958, continued into 1959...
Keywords: AERODYNAMICS; BOUNDARY LAYERS; SEPARATED FLOW; AXISYMMETRIC FLOW; BOUNDARY CONDITIONS; COMPUTATION; INVISCID FLOW; NUMERICAL ANALYSIS; VISCOUS FLOW
Downloads: 103
[texts]Effective Thermal Conductivity of High Porosity Open Cell Nickel Foam - Sullins, Alan D.
The effective thermal conductivity of high-porosity open cell nickel foam samples was measured over a wide range of temperatures and pressures using a standard steady-state technique. The samples, measuring 23.8 mm, 18.7 mm, and 13.6 mm in thickness, were constructed with layers of 1.7 mm thick foam with a porosity of 0.968. Tests were conducted with the specimens subjected to temperature differences of 100 to 1000 K across the thickness and at environmental pressures of 10(exp -4) to 750 mm Hg...
Keywords: BOUNDARY CONDITIONS; COMPUTATION; POROSITY; SIMULATION; MATHEMATICAL MODELS; AERODYNAMICS; AGGREGATES; LEADING EDGES; FOREBODIES; COST REDUCTION
Downloads: 127
[texts]The Ionized Gas and Nuclear Environment in NGC 3783 - Netzer, Hagai
We present a detailed analysis of the 900 ks spectrum of NGC3783 obtained by Chandra in 2000-2001 (Kaspi et al. 2002). We split the data in various ways to look for time dependent and luminosity dependent spectral variations. This analysis, the measured equivalent widths of a large number of X-ray lines, and our photoionization calculations, lead us to the following conclusions: 1) NGC 3783 fluctuated in luminosity, by a factor N 1.5, during individual 170 ks observations...
Keywords: BOUNDARY CONDITIONS; PLANE WAVES; CONSERVATION LAWS; WAVE PROPAGATION; REFLECTION; HYPERBOLIC SYSTEMS; EULER EQUATIONS OF MOTION
Downloads: 65
[texts]A preliminary investigation of the use of throttles for emergency flight control - Burcham, F. W., Jr.
A preliminary investigation was conducted regarding the use of throttles for emergency flight control of a multiengine aircraft. Several airplanes including a light twin-engine piston-powered airplane, jet transports, and a high performance fighter were studied during flight and piloted simulations. Simulation studies used the B-720, B-727, MD-11, and F-15 aircraft. Flight studies used the Lear 24, Piper PA-30, and F-15 airplanes...
Keywords: APPROXIMATION; EXPONENTIAL FUNCTIONS; NUMERICAL STABILITY; WAVE EQUATIONS; BOUNDARY CONDITIONS; DAMPING; FINITE DIFFERENCE THEORY; FINITE ELEMENT METHOD
Downloads: 99
[texts]Apollo by the Numbers: A Statistical Reference - Orloff, Richar
The purpose of this work is to provide researchers, students, and space enthusiasts with a comprehensive reference for facts about Project Apollo, America's effort to put humans in the Moon. Research for this work started in 1988, when the author discovered that, despite the number of excellent books that focused on the drama of events that highlighted Apollo, there were none that focused on the drama of the numbers...
Keywords: LIQUID SURFACES; SEAPLANES; AMPHIBIOUS AIRCRAFT; WATER LANDING; AIRCRAFT LANDING; SLIDING; BOUNDARY CONDITIONS; INTERFACIAL TENSION
Downloads: 538
[texts]Phenomena Associated with Impacts and Sliding on Liquid Surfaces - Wagner, Herber
The matter dealt with in the present paper has a direct bearing on the taking-off and alighting of seaplanes. The liquid is assumed as being non-viscous and incompressible, and the acceleration due to gravity is neglected. The following considerations therefore apply the more exactly the smaller the body and the more quickly it moves. In the case of prolonged. and primarily of uniform processors, the arguments hold only in the close neighborhood of the body...
Keywords: AEROACOUSTICS; SOUND WAVES; VORTEX SHEDDING; NUMERICAL ANALYSIS; SIMULATION; BOUNDARY CONDITIONS; OPENINGS
Downloads: 213
[texts]Concept for a Micro Autonomous Ultrasonic Instrument (MAUI) - Wilson, William C.
We investigate a concept for the construction a mobile Micro Optical ElectroMechanical Systems (MOEMS) based laser ultrasonic instrument to serve as a Micro Autonomous Ultrasonic Instrument (MAUI). The system will consist of a laser ultrasonic instrument fabricated using Micro Electro-Mechanical Systems (MEMS) technology, and a MEMS based walking platform like those developed by Pister et al. at Berkeley...
Keywords: BOUNDARY CONDITIONS; BUCKLING; DEFORMATION; LAMINATES; PLATES (STRUCTURAL MEMBERS); NONLINEAR SYSTEMS; PLY ORIENTATION; DISPLACEMENT
Downloads: 67
[texts]Model Checking Real Time Java Using Java PathFinder - Lindstrom, Gary
The Real Time Specification for Java (RTSJ) is an augmentation of Java for real time applications of various degrees of hardness. The central features of RTSJ are real time threads; user defined schedulers; asynchronous events, handlers, and control transfers; a priority inheritance based default scheduler; non-heap memory areas such as immortal and scoped, and non-heap real time threads whose execution is not impeded by garbage collection...
Keywords: SPACE-TIME FUNCTIONS; FINITE DIFFERENCE THEORY; ELECTROMAGNETIC RADIATION; COSMOLOGY; BOUNDARY CONDITIONS; WAVE PROPAGATION; CONTROLLERS
Downloads: 91
[texts]Numerical predictions of nonlinear diffusion with homogeneous recombination and time- varying boundary conditions - Reinhardt, W. A
Numerical predictions of nonlinear diffusion with homogeneous recombination and time-varying boundary conditions
Keywords: BOUNDARY CONDITIONS; RECOMBINATION; DIFFUSION; HOMOGENEITY; NONLINEARITY; NUMERICAL ANALYSIS; PREDICTIONS; TIME; VARIATIONS; DIFFUSION
Downloads: 71
[texts]Static test induced loads verification beyond elastic limit - Verderaime, V.
Increasing demands for reliable and least-cost high performance aerostructures are pressing design analyses, materials, and manufacturing processes to new and narrowly experienced performance and verification technologies. This study assessed the adequacy of current experimental verification of the traditional binding ultimate safety factor which covers rare events in which no statistical design data exist...
Keywords: MSM (SEMICONDUCTORS); THERMIONIC EMISSION; ALUMINUM GALLIUM ARSENIDES; EPITAXY; GALLIUM ARSENIDES; HETEROJUNCTIONS; BOUNDARY CONDITIONS; DIFFUSION; PHOTOMETERS; SUBSTRATES
Downloads: 56
[texts]Vapor Compression Distillation Subsystem (VCDS) component enhancement, testing and expert fault diagnostics development, volume 1 - Kovach, L. S.
Vapor compression distillation technology for phase change recovery of potable water from wastewater has evolved as a technically mature approach for use aboard the Space Station. A program to parametrically test an advanced preprototype Vapor Compression Distillation Subsystem (VCDS) was completed during 1985 and 1986. In parallel with parametric testing, a hardware improvement program was initiated to test the feasibility of incorporating several key improvements into the advanced preprototype...
Keywords: BARS; BOUNDARY CONDITIONS; BOUNDARY VALUE PROBLEMS; MATHEMATICAL MODELS; PROBLEM SOLVING; VIBRATION; FREQUENCIES; SPRINGS (ELASTIC)
Downloads: 150
[texts]Investigations on Experimental Impellers for Axial Blowers - Encke, W
A selection of measurements obtained on experimental impellers for axial blowers will be reported. In addition to characteristic curves plotted for low and for high peripheral velocities, proportions and blade sections for six different blower models and remarks on the design of blowers will be presented.
Keywords: CONICAL FLOW; SUPERSONIC FLOW; AIRCRAFT DESIGN; DIFFERENTIAL EQUATIONS; MACH CONES; GAS FLOW; BOUNDARY CONDITIONS
Downloads: 57
[texts]Results of some initial space qualification testing on triple junction a-Si and CuInSe2 thin film solar cells - Mueller, Robert L.
A series of environmental tests were completed on one type of triple junction a-Si and two types of CuInSe2 thin film solar cells. The environmental tests include electron irradiation at energies of 0.7, 1.0, and 2.0 MeV, proton irradiation at energies of 0.115, 0.24, 0.3, 0.5, 1.0, and 3.0 MeV, post-irradiation annealing at temperatures between 20 C and 60 C, long term exposure to air mass zero (AM0) photons, measurement of the cells as a function of temperature and illumination intensity, and ...
Keywords: COMPRESSING; OSCILLATORS; PARAMETRIC AMPLIFIERS; QUADRATURES; QUANTUM OPTICS; SQUEEZED STATES (QUANTUM THEORY); BOUNDARY CONDITIONS; CAVITIES; Q FACTORS
Downloads: 77
[texts]Education and Public Outreach - NON
This Annual Report is a summary of nearly 400 Education and Public Outreach (E/PO) products and activities developed or carried out in FY2000 under NASA's Office of Space Science (OSS) E/PO program. It includes products and activities developed by OSS missions and research programs, innovative space science concepts developed under the Initiative to Develop Education through Astronomy and Space Science (IDEAS) Program, projects initiated under the Minority University Education and Research Partn...
Keywords: COMPUTATIONAL GRIDS; COMPUTATIONAL FLUID DYNAMICS; NONLINEAR SYSTEMS; BOUNDARY CONDITIONS; AERONAUTICAL ENGINEERING; CONVERGENCE; SIMULATION; TVD SCHEMES; SPACING
Downloads: 186
[texts]Nature and origin of secondary mineral coatings on volcanic rocks of the Black Mountain, Stonewall Mountain, and Kane Springs Wash volcanic centers, southern, Nevada - Taranik, James V.
The following subject areas are covered: (1) genetic, spectral, and LANDSAT Thematic Mapper imagery relationship between desert varnish and tertiary volcanic host rocks, southern Nevada; (2) reconnaissance geologic mapping of the Kane Springs Wash Volcanic Center, Lincoln County, Nevada, using multispectral thermal infrared imagery; (3) interregional comparisons of desert varnish; and (4) airborne scanner (GERIS) imagery of the Kane Springs Wash Volcanic Center, Lincoln County, Nevada.
Keywords: ACOUSTICS; FREQUENCY RANGES; TIME; BOUNDARY CONDITIONS; DUCTS; REFLECTANCE; SOUND WAVES; WALLS; WEDGES; COMPARISON; FOAMS
Downloads: 200
[texts]Investigation of the Thermomechanical Response of Shape Memory Alloy Hybrid Composite Beams - Davis, Brian A
Previous work at NASA Langley Research Center (LaRC) involved fabrication and testing of composite beams with embedded, pre-strained shape memory alloy (SMA) ribbons. That study also provided comparison of experimental results with numerical predictions from a research code making use of a new thermoelastic model for shape memory alloy hybrid composite (SMAHC) structures. The previous work showed qualitative validation of the numerical model...
Keywords: COMPUTATIONAL FLUID DYNAMICS; CONVERGENCE; BOUNDARY CONDITIONS; LAPLACE EQUATION; ALGORITHMS; PARTIAL DIFFERENTIAL EQUATIONS; MATHEMATICAL MODELS
Downloads: 95
[texts]Appendices B thru F, volume 3 - NON
The purpose of this investigation was to determine if the intermodule ventilation (IMV) systems and water distribution systems of Space Station Freedom (SSF) modules and nodes should be connected as they are interfaced with those already in operation. It was concluded that the AC configuration and attached LAB and HAB modules and nodes should be interconnected. The H2O circuits should also be interconnected...
Keywords: ELASTIC PLATES; THICKNESS; ELASTIC PROPERTIES; HIERARCHIES; LAMINATES; MATHEMATICAL MODELS; PLY ORIENTATION; RECTANGULAR PLATES; BENDING; BOUNDARY CONDITIONS
Downloads: 84
[texts]Turbine Engine Hot Section Technology (HOST) - NON
A two-day workshop on the research and plans for turbine engine hot section durability problems was held on October 25 and 26, 1983, at the NASA Lewis Research Center. Presentations were made during six sessions, including structural analysis, fatigue and fracture, surface protective coatings, combustion, turbine heat transfer, and instrumentation, that dealt with the thermal and fluid environment around liners, blades, and vanes, and with material coatings, constitutive behavior, stress-strain ...
Keywords: DEFORMATION; NONLINEARITY; TRANSFORMATIONS (MATHEMATICS); VISCOELASTICITY; BOUNDARY CONDITIONS; BOUNDARY VALUE PROBLEMS; CONVOLUTION INTEGRALS; DIFFERENTIAL EQUATIONS; PROBLEM SOLVING
Downloads: 233
[texts]Wavelength Division Multiplexing Scheme for Radio-Frequency Single Electron Transistors - Stevenson, Thomas R.
We describe work on a wavelength division multiplexing scheme for radio-frequency single electron transistors. We use a network of resonant impedance matching circuits to direct applied rf carrier waves to different transistors depending on carrier frequency. Using discrete components, we made a two-channel demonstration of this concept and successfully reconstructed input signals with small levels of cross coupling...
Keywords: COMPUTER PROGRAMS; AERODYNAMICS; COMPUTATIONAL FLUID DYNAMICS; COMPUTATIONAL GRIDS; INPUT/OUTPUT ROUTINES; BOUNDARY CONDITIONS; FLOW EQUATIONS; TIME DEPENDENCE
Downloads: 72
[texts]Mapping Closure Approximation to Conditional Dissipation Rate for Turbulent Scalar Mixing - He, Gouwei
A novel mapping closure approximation (MCA) technique is developed to construct a model for the conditional dissipation rate (CDR) of a scalar in homogeneous turbulence. It is shown that the CDR model from amplitude mapping closure is incorrect in asymptotic behavior for unsymmetric binary mixing. The correct asymptotic behavior can be described by the CDR model formulated by the MCA technique. The MCA approach is outlined for constructing successive approximation to probability density function...
Keywords: AERODYNAMIC CHARACTERISTICS; CONTROL EQUIPMENT; DESIGN ANALYSIS; POROSITY; COMPUTATIONAL FLUID DYNAMICS; BOUNDARY CONDITIONS; LATERAL CONTROL; LOW SPEED; TAILLESS AIRCRAFT
Downloads: 65
[texts]Software dependability in the Tandem GUARDIAN system - Lee, Inhwan
Based on extensive field failure data for Tandem's GUARDIAN operating system this paper discusses evaluation of the dependability of operational software. Software faults considered are major defects that result in processor failures and invoke backup processes to take over. The paper categorizes the underlying causes of software failures and evaluates the effectiveness of the process pair technique in tolerating software faults...
Keywords: ACCRETION DISKS; ASTROPHYSICS; MAGNETIC FIELD RECONNECTION; INTERNAL WAVES; MAGNETOHYDRODYNAMIC STABILITY; BOUNDARY CONDITIONS; PLASMA PHYSICS; TIDAL WAVES; ROTATING DISKS
Downloads: 90
[texts]The effect of 1/2 MeV electron radiation on the crystallinity of graphite fibers in composites - Kent, M.
No Abstract Available
Keywords: COMPUTATIONAL FLUID DYNAMICS; FINITE DIFFERENCE THEORY; VISCOSITY; BOUNDARY CONDITIONS; BOUNDARY VALUE PROBLEMS; CONSERVATION LAWS; SHOCK WAVES; WAVE EQUATIONS
Downloads: 58
[texts]Power Budget Analysis for High Altitude Airships - Choi, Sang H.
The High Altitude Airship (HAA) has various potential applications and mission scenarios that require onboard energy harvesting and power distribution systems. The energy source considered for the HAA s power budget is solar photon energy that allows the use of either photovoltaic (PV) cells or advanced thermoelectric (ATE) converters. Both PV cells and an ATE system utilizing high performance thermoelectric materials were briefly compared to identify the advantages of ATE for HAA applications i...
Keywords: SENSITIVITY ANALYSIS; COMPRESSIBILITY; BOUNDARY CONDITIONS; STRUCTURAL ANALYSIS; PANELS; DESIGN ANALYSIS; PERFORMANCE TESTS; STRUCTURAL DESIGN; TENSILE STRESS; FABRICATION; DISPLACEMENT
Downloads: 75
[texts]Analysis of LDEF experiment AO187-2 chemical and isotopic measurements of micrometeoroids by secondary ion mass spectrometry - Zinner, Erns
#Experiment AO187-2, that was flown on board the Long Duration Exposure Facility(LDEF), was designed to measure the chemical and isotopic compositions of interplanetary dust impinging on the spacecraft from outer space. Information on the nature and composition of orbital debris was also anticipated. The spacecraft maintained a constant orientation with respect to its velocity vector thereby defining leading and trailing edges that faced respectively into and away from the direction of motion...
Keywords: ACOUSTIC PROPAGATION; FLUID FLOW; NONLINEARITY; AEROACOUSTICS; COMPUTATIONAL FLUID DYNAMICS; CONFERENCES; SOUND FIELDS; SOUND WAVES; BOUNDARY CONDITIONS; COMPUTERIZED SIMULATION; DISSIPATION
Downloads: 56
[texts]The Evolution of CTB109. A Study of the Composite Remnant MSH15-56. - Plucinsky, Pau
The subject grant is for the analysis of ASCA observations of two well-known galactic Supernova Remnants, CTB 109 and MSH 15-56. The purpose of the proposal is to study spectral differences as a function of position within each of the remnants. For CTB 109 we are attempting to understand how the unusual semi-circular structure evolved. For MSH 15-56, we are attempting to understand the nature of the emission in the bright central region and around the outer edge of the remnant.
Keywords: GULF STREAM; VORTICES; OCEAN MODELS; OCEAN SURFACE; SATELLITE ALTIMETRY; MATHEMATICAL MODELS; GEOSAT SATELLITES; HYDROGRAPHY; BOUNDARY CONDITIONS; TOPOGRAPHY
Downloads: 52
[texts]Space Vehicle Power System Comprised of Battery/Capacitor Combinations - Camarotte, C.
Recent improvements in energy densities of batteries open the possibility of using electric rather that hydraulic actuators in space vehicle systems. However, the systems usually require short-duration, high-power pulses. This power profile requires the battery system to be sized to meet the power requirements rather than stored energy requirements, often resulting in a large and inefficient energy storage system...
Keywords: CARTESIAN COORDINATES; GRID GENERATION (MATHEMATICS); THREE DIMENSIONAL FLOW; BOUNDARY CONDITIONS; UNSTEADY FLOW; ALGORITHMS; ROBUSTNESS (MATHEMATICS); SIMPLIFICATION; SIMULATION
Downloads: 80
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